SEOUL, Nov. 8 (Yonhap) -- The Koreas agreed Thursday to each retain one of the 11 border guard posts they have selected for "complete demolition" due to their historical symbolism, Seoul's defense ministry said.

During their general-grade military talks last month, they agreed to each withdraw 11 guard posts in the Demilitarized Zone by the end of this month and verify their removal in December in line with their September military agreement aimed at building trust, reducing tensions and preventing accidental clashes.

The South selected one guard post, built on the east coast in 1953, due to its historical value and its possible utility in promoting peace, Seoul officials said. The North opted for one in its central border region based on its own criteria, they said.

Despite the decision to retain the two guard posts, the South and the North will withdraw all weapons and other military equipment from them.

"The South's and the North's military authorities will make necessary efforts to ensure that the withdrawal plan will be completed by the end of December while devising measures to enhance mutual trust and transparency in the process of removing the guard posts on a trial basis," the ministry said.

The Koreas' defense ministers signed the inter-Korean military agreement after the third summit between President Moon Jae-in and North Korean leader Kim Jong-un in Pyongyang in September.

The agreement also includes disarming the Joint Security Area in the DMZ, conducting a joint project to excavate Korean War remains in a DMZ battle site and setting up ground, air and maritime buffer zones.

Meanwhile, the defense ministry told an opposition lawmaker that the enforcement of the military agreement is estimated to cost an additional 10.1 billion won (US$9.04 million) next year.

The ministry said that it is expected to need some 15 billion won to implement the agreement until next year. It has already set aside around 4 billion won from this year's government budget. But it has not earmarked the 10.1 billion won yet in its budget proposal for next year.